Many forms of wire strippers are known in the art, with a wide variety of strippers, both manually operated and automatic, being employed in the removal of insulation from the conductor or conductors utilized in an electrical wire.
In many types of insulation, mechanical type wire strippers work quite well, for in the instance in which the wall thickness is comparatively great, the blades of a mechanical device can be set to cut say 80% of the way through the insulation, and thereafter the end portion of the insulation pulled on to cause severing of the insulation at the weakened location. Properly operating mechanical strippers of this type do not damage the conductor as long as the blades stop short of contacting the conductor.
The problem of insulation removal is intensified, however, when in the saving of space, designers call for the use of conductors having thinwalled insulation. This is so because it is virtually impossible to design and operate mechanical blades that will cut through thin-wall insulation sufficiently far that the insulation can thereafter be pulled apart at the proper location, without the blades from time to time damaging the conductor.
For reasons of the inadequacy of mechanical strippers for use in connection with the stripping of thin wall insulation and the like, there has been an increased use of hot wire type strippers, which involve one or two heated filaments that can be brought into contact with the insulation, to cause degrading thereof at a desired location. The hot wire type stripper, if properly used, enables thin walled insulation to be removed without damaging the conductor, but by and large, a noncontrolled stripping operation is involved, with the skill of the operator in properly removing the insulation being entailed to a marked degree if damage to the insulation remaining on the wire is to be avoided.
A particularly challenging problem is involved when the insulation to be stripped is made of asbestos, woven glass, some combination of these, or the combination of one of these with another material. Both the mechanical type stripper as well as the hot wire stripper are inadequate in most such instances, and to the best knowledge of the present inventors, the only acceptable procedure for removing many of the tough, high temperature insulations such as Kapton, H-Film and the like is by an operator utilizing a knife. This obviously is a slow and tedious procedure, with the conductor or conductors inside the insulation being removed, often being nicked or otherwise damaged during the stripping procedure.